So this idea is really quite simple, will bring a coin sink (so players spend more coins and are incentivized to donate more) and would be a really nice addition to the game without causing any serious change in it.
Idea: Unlike allowing players to have extra talent points that make them stronger or having extra professions that give benefits to players,
***I recommend implementing a triple specialization bonus on the talent tree unlockable via coins. ***
Benefits:
-Players will donate more
-Players will not complain that it is changing game balance in anyway as it's simply dual spec, but a third spec.
-This will introduce an element of enjoyment for players who:
-Primarily pve to be able to fill more roles in dungeon and ques would be less long,
-Raiding would be easier to form as players build their third spec and people can enjoy wiping instead of spending hours forming a raid
-PvP would be more fair for players who prioritize pve as they can have a pvp spec.
-More players would run dungeons for a third spec
Cons:
-Possibly making only 1 toon of every class to experience the entirety of the class may have a drawback I, myself, am unable to see
-Players who don't donate or buy coins via trading are unable to experience this
-This would be a premium benefit that could have some negative reaction from free to play players
Overall Triple spec would ONLY be a quality of life change.
EDIT: As many believe I ment it's a donator-only (premium option) this is not what I ment. I ment for it to be accessible for players to purchase only with coins, which may obviously be aquired with gold via trade.